Burglar alarm systems



July 11, 1967 R. E. ROWE 3,330,92

BURGLAR ALARM SYSTEMS Filed Feb. 11, 1965 TO SIGNALLING TRANSMITTER ANDCENTRAL STATION INVENTOR. ROBERT E. ROWE ATTORNEY the roll-curtainusually slides Some of these protective devices United States Patent3,330,922 BURGLAR ALARM SYSTEMS Robert E. Rowe, 4402 Mount Linsey St.,San Diego, Calif. Filed Feb. 11, 1965, Ser. No. 431,877 6 Claims. (Cl.20061.93)

The present invention relates to burgular alarm systems and moreparticularly to burglar alarm systems that may be used for signaling theopening movement of rollcurtain doors or the like.

A roll-curtain type door is a flexible door that is often used to closeexisting openings in warehouses and other type storage areas that aresubject to burglaries. The flexible door or roll-curtain is moved toopen or close the openings by being rolled on a rotating shaft similarto a window shade. The roll-curtain, when in the retracted or rolled upposition, is concentrically wound around the shaft and resides within ahousing. In this position only the bottom member or plate of therollcurtain is left exposed. When in the extended position down betweenlongitudinal guide plates that are attached to the wall of the opening,and the bottom plate rests on the floor or is close to the floor. Thusin using the roll-curtain door the flexible roll-curtain is rolled up ona rotating axle at the top of the door construction with the flexiblecover being retracted into or extended from the housing.

In the past it has been the practice in this field to use any of severaltypes of protective devices to signal a burglar type entry attemptthrough roll-curtain doors.

have been mechanically operated, some magnetically operated and someeven utilize a radioactive source as the actuating element in anelectric eye type detection system. However, all of the aforesaiddevices cause difiiculties both in installation and in maintenance thatwould be very advantageous to correct. These difliculties arise for mayreasons, one being the physical location where it is necessary to placethe protective devices. Normally the protective device actuating elementis placed on the bottom plate of the roll-curtain and the cooperativeprotective device is secured to the bottom portion of the doorslongitudinal guide plates. Installing protective devices on the bottomportion of the roll-curtain door construction subjects the protectivedevices or their actuating elements to mechanical damage or disablementfrom dust, dirt, water, or product spillage.

For example, in magnetic type alarm systems for rollcurtain doors, themagnetic actuating elements and the cooperative protective devices mustbe in alignment and closely positioned. Separation or misalignment ofthe two members signals the burglar alarm. The two members are usuallymounted, because of necessity, on the bottom or bottom side of theroll-curtain type door. The bottom of the flexible roll-curtain in mostinstallations can be moved sideways by Wind or other causes, not arisingbecause of an attempted burglary. The spacing between the edge of theroll-curtain and the frame members permit this movement, which movementcan cause the burglar alarm to be signaled, giving a false alarm. Thebottom of the roll-curtain can even be moved vertically by wind or thelike, causing an alarm. Further, the door is metal and this, over aperiod of time, reduces or disrupts the effective magnetic power of thesystem. In other type burglar alarm systems such as, for example, theone that uses radioactive material in the manner of an electric eye,such systems are also plagued with the same type of end play or sideplay of the roll-curtain that causes misalignment of the path orextension of its length, thereby reducing the amount of radioactivitypassing from the actuating member to the protective device. Theoccurrence of such misalignments that are of sufiicient nature toenergize the burglar alarm but are not caused by attempted burglaries,eventually cause lack of faith in the system.

In addition, in older roll-curtain enclosures, the rollcurtain and itscasings are often not fitted for a burglar alarm system. Thus to installthe prior art systems, it is necessary to cut out portions of the wallor floor around the flexible door and make physical alterations to thedoor. Even with these expensive changes, the protective devices stillproject from the wall or floor, or from the roll-curtain, and aresubject to being knocked oif or damaged by vehicles and the like thatpass through the door. Accordingly, it may be seen that because ofproblems resulting from the elements, from the amount of installationexpense, and from physical damage, the prior art devices have seriouslimitations.

It is therefore an object of this invention to provide a novel andimproved burgular alarm protective device for use with roll-curtain typedoors or the like that overcomes many of the difliculties involved inusing other burglar alarm protective devices.

It is another object of this invention to provide a novel and improvedburglar alarm protective device that may be installed on roll-curtaintype doors or the like Without alteration to the door, the door casing,or interfering with the normal operation of the door.

It is another object of this invention to provide a novel and improvedburglar alarm protective device for a roll-curtain door or the like thatmay be readily and easily adjusted to provide burglar alarm protectionfor any of an infinite number of selective extensions of theroll-curtain door or the like.

It is another object of this invention to provide a novel and improvedburglar alarm protective device for roll-curtain doors or the like,which device is located entirely within the building in which it isinstalled, and is removed from possible contact with vehicles in theirnormal movement through the door.

It is another object of this invention to provide a novel and improvedburglar alarm protective device for roll-curtain doors and the like thatdoes not signal the burglar alarm when the or shaken by wind.

' It is another object of this invention to provide a novel and improvedburglar alarm protection device for roll-curt-ain doors or the like thatmay be moved from door to door in an easy, quick, .and inexpensivemanner.

It is another object of this invention to provide a novel and improvedburgular alarm protective device for rollcurtain doors and the like thatis simple and inexpensive in construction and requires no specialtechnical knowledge to install, adjust, or maintain.

It is another object of this invention to provide a novel and improvedburglar alarm protective device for roll curtain doors and the like thatis not effected in operation by the proximity of metal or othersub-stances, and that does not require any additional sourceof'electrical power for operation.

roll-curtain or the like is moved chain 22 in the well known manner.

It is another object of this invention to provide a novel and improvedswitch actuating mechanism.

This invention generally comprises a switching mechanism that may beremovably attached to or fixed to the axle shaft on, which aroll-curtain door or the like is rolled up or down to open and closedpositions. The switching mechanism includes a rotatable threaded memberthat is fixed to or attached to the axle shaft and rotated therewith. Afollower member having internal threads corresponding to the threads onthe threaded member is screwed into the threaded member and ininstallation is prevented from movement around the threaded member whenthe threaded member is rotated by the axle shaft of the roll-curtaindoor. Thus the follower member is moved linearly along the longitudinalaxis of the threaded member in response to rotation of the latter.Linear movement of the follower member corresponds with verticalmovement of the roll-curtain. So, upon a given movement of theroll-curtain, the follower member activates a switch to open or closedposition as may be desired to reflect the position of the roll-curtaindoor. In roll-curtain door installations the switching curcuit actuatesthe burgular alarm. Thus a given movement of the roll-curtain and thefollower member will actuate the burgular alarm.

After the roll-curtain door is installed, the burglar alarm system ofthis invention may be attached to the wall of the building with thethreaded member secured to the axle shaft of the roll-curtain door. Thefollower member is then adjusted so that the follower member will openthe burglar alarm circuit at that point of rotation of the threadedmember that corresponds to the bottom of the roll-curtain door coming incontact with or close to the bottom of the opening to be closed. Therelative positions of the switch and the follower member may. beselectively varied to correspond with the burglar alarm actuation atselected positions of the roll-curtain. This installation has a highlocation and thus avoids many of the disadvantages in having burglaralarm protection devices at a low level. Dust, dirt, and water no longerpose problems when using this invention. Also malicious tampering isimpractical at its high level location and guards and shields formechanical protection are not necessary. Further, no additionalelectrical power is required for the operation of this protective deviceas it derives all of its rotational power from the axle shaft. Stillfurther, no

permanent installations are necessary for the use of this system.

Other objects, features, and advantages of the invention will appearmore fully from the following description that is described in detailwith reference to the appending drawing wherein like reference numeralsdesignate like parts throughout, and in which:

FIGURE 1 is an elevation view of one side of a rollcurtain door thatshows the location of installation of the invention thereon.

FIGURE 2 is a sectional view taken along one side of the switchactuating mechanism of this invention.

FIGURE 3 is a part sectional view taken along line 3-3 of FIGURE 2.

FIGURE 4 is a schematic diagram illustrating the electrical circuit ofthe switch actuating mechanism of this invention.

Referring now to the drawing and to FIGURE 1, there is shown aroll-curtain door, 10, with only a side portion illustrated. The otherside of the door would, of course, follow the same type of constructionas is well known in the art. In roll-curtain doors of this type thedoor-proper, '12, is made of metal sections that are flexibly secured,one to the other, and may be rolled up around an axle shaft, 14, shownin section. This function is similar to rolling up a window shade. Theaxle shaft is rotated by a gear, 16, that is rotated by following gear18 that is'driven by driving gear 20. Driving gear 20 is rotated by apull The flexible door, in ssing from its closed to open positions andthen back to wherein leaf member the closed position, is guided byhaving its edges inbetween metal frame members 24 that are secured to awall by metal bracket members 26.

The roll-curtain door is rolled up into housing 28 and around axle shaft14. The drive mechanism 22, housing 28, and axle shaft 14, are allwithin the building to which the roll-curtain door closes the opening.Thus there is easy straight forward access to the axle shaft 14 withinthe building. The burglar alarm protective device of this invention ismounted by bracket 30 to the inner side of the building wall and isattached directly to the axle shaft 14. Rod 42 may be fixed to shaft 14permanently such as by welding, or it may be removab-ly secured to shaft14 by brackets. The attachment shown in FIGURE 1 is by brackets. Rod 42is secured to plate 44 by a collar having a normal locking screw. Plate44 is secured to gear 16 and shaft 14 by hook members 46 that are pulledagainst the spokes of gear 16 by a normal threaded nut arrangement.

Referring now to FIGURE 2, there is shown an embodiment of the burglaralarm switch of this invention, 32, that comprises a box, 34, that maybe of rigid and water proof construction and made of metal, plastic, orthe like. The box, 34, is closed except for an opening, 36, at one endthat receives an externally threaded plug member 38 having a bearingaperture 40 that passes therethrough. Passing through bearing 40 isconnecting rod 42 that is fixed to the roll-curtain axle shaft 14, aspreviously described.

A threaded member, 48, having a coarse thread, 50, is integral with rod42 at one end and at the other end is held by bearing member 52 to theback side of box 34. Bearings 40 and 52 maintain rotational alignment ofthe threaded member 48. Threaded on member 48 is a follower member 54that has internal coarse threads cut therein corresponding with thecoarse threads 50 on threaded member 48. The follower member 54 has aflat lower surface 56 that slideably contacts the flat lower surface 58of the box 34. This cooperation of surfaces prevents rotational movementby follower member 54. Upon rotational movement of the roll-curtain axleshaft 14, rod 42 is rotated, thereby rotating the threaded rod 48. Thiscauses follower member 54 to move linearly along the length of thethreaded member 48.

A switch mechanism, 60, is mounted on the end of the box 34 and adjacentto the threaded member 48. In this position, it may be contacted by theprojection 62 on the follower member 54. As may be seen, the switchingmechanism shown in the specific embodiment of the invention, comprisesleaf springs 64 with electrical connections 66 on the ends thereof. Theleaf springs, 64, are rigidly held by insulating blocks 68 and securedto the attaching member 70. The center leaf spring, 74, has a downwardlyprojecting contact member 72 that, when moved linearly by projection 62,causes one electrical connection to break and another electricalconnection to make in the electrical circuit of the burglar alarm.Referring to FIGURE 4, the particular electrical circuit is shown 74corresponds with movable contact member 74 of FIGURE 4, and leaf members76 and 78 correspond to electrical connections 76' and 78'. Theelectrical circuit of FIGURE 4 functions to switch electricity in a wellknown manner in a central station to actuate a bulglar alarm in anappropriate and well known manner.

Operation In operation, this invention may be installed on existingroll-curtain doors or may be installed at the time the roll-curtain dooris installed. The switching box, 32, is mounted onto a wall adjacent theroll-curtain door and connecting rod 42 is secured to the axle shaft 14.The rollcurtain door is then rolled to a closed position with the bottommember, 80, in contact with, or very close to, the floor surface 82. Inthis position the location of the follower member 54 is adjusted alongthreaded member 48 so that projection 62 contacts the actuating member72 of the leaf spring 74 and forces contact 66 of leaf spring 27 awayfrom the contact 66 on leaf spring switch 64 and into contact withconnection 78. With this positioning of the follower member 54, upon anyupward movement of the roll-curtain door 12, there will be acorresponding and necessary rotation of the axle shaft 14 that in turnrotates rod 42 and threaded member 48, thereby moving follower member 54away from the spring contact member 72, and allowing the spring contactmember 74 to make electrical contact with the spring member 76,actuating the burglar alarm. The exact positioning of the followermember 54 may be varied relative to the position of the roll-curtain byvarying the connection between the axle shaft 14 and rod 42.

While the switching system of this invention has specific novel andunique application to burglar alarm systems used on roll-curtain doorsand the like, it also has general application.

The features and principles of the invention described herein inconnection with the specific exemplification thereof will suggest tothose skilled in the art other ways for designing and arrangingprotective systems in accordance with the invention. It is acordinglydesired that the appended claims be given a construction commensuratewith the scope of the invention within the I claim:

1. A switching system in a burglar alarm system for signaling openingmovement of a roll-curtain door or the like upon opening or closing anelectrical circuit in response to given rotational movement of theroll-curtain door shaft, comprising;

a threaded member having internal threads that are capable of beingrotated by said shaft,

a follower member having external threads that is mounted on saidthreaded member,

means for preventing rotation of said follower member around saidthreaded member,

and switch means in said electrical circuit being positioned adjacentsaid threaded member for being actuated through contact with saidfollower member.

2. A burglar alarm system for signaling opening movement of aroll-curtain door or the like, comprising;

a switch for opening and closing an electrical circuit in response togiven rotational movement of the shaft of said roll-curtain door,

said switch having a threaded member with a threaded external surfacewhich member is capable of being rotated by said shaft,

a follower member having a flat surface on one of its sides and beingmounted on said threaded member and having internal threadscorresponding to and coacting with said external thread on said threadedmember,

flat sruface means being positioned adjacent said follower member andco-acting with said flat surface on said follower member to preventrotation of said follower member upon rotation of said threaded member,

and switch means in said electrical circuit being positioned adjacentsaid threaded member and being actuated through contact with saidfollower member when said follower member is moved linearly by rotationof said threaded member.

3. A burglar alarm system for signaling opening movement of aroll-curtain door or the like, comprising;

a threaded member having an external thread, said threaded member beingcapable of being secured to the shaft on which said roll-curtain door orthe like is rolled upon and being rotated by said shaft,

a follower member having an internal thread and being mounted on saidthreaded member,

means for preventing rotation of said follower member upon rotation ofsaid threaded member,

circuit means for actuating said burglar alarm system,

and said circuit means being capable of being actuated by said followermember in response to said threaded member being rotated by said shaft.

4. A burglar alarm system for signaling opening move ment of aroll-curtain door or the like that is rolled up or down on a rotatableshaft, comprising;

a box like member having an opening in one end and an internalrelatively flat surface on one side,

a threaded member extending through said opening in said box like memberand being capable of being rotated by said rotational movement of saidshaft,

a follower member having a coarse internal thread that is mounted onsaid threaded member and is moved along the axis of said threaded memberupon rotation of said threaded member,

said follower member having a flat surface on one side thereof forco-acting with said flat surface of said box like member,

switch means located in said box like member adjacent the path ofmovement of said follower member for being actuated by said followermember, and signaling said burglar alarm,

and said follower member actuating said switch means upon said closedroll-curtain door being opened a given amount.

5. A burglar alarm system for signaling opening movement of aroll-curtain door or the like that is rolled up or down on a rotatableshaft, comprising;

a box like member secured to a fixed part of the build ing on which saiddoor is mounted at a location adjacent said door,

said box like member having an internal flat side and an opening in theend adjacent said roll-curtain door,

a threaded member for being connected to said shaft and be rotatedtherewith,

said threaded member being located in said box like member and having acoarse external thread,

a follower member having a coarse internal thread and being mounted onsaid threaded member,

said follower member having a substantially flat surface on one side forco-acting with said fiat side of said box like member which co-actionprevents rotation of said follower member around said threaded member,

and switch means in said box like member being capable of beingcontacted by said follower member for con trolling said burglar alarm.

6. A burglar alarm system for signaling opening movement of aroll-curtain door or the like that is rolled up or down on a rotatableshaft, comprising;

a box like member being secured to the building on which said door ismounted at a location adjacent said door and in substantial alignmentwith said shaft,

one of the sides of said box like member being substantially fiat,

said box like member having an opening in the end thereof adjacent saidshaft with a connecting rod projecting therethrough that is releasablyconnected to said shaft,

said connecting rod being integral with a threaded member having acoarse external thread,

a follower member having a coarse internal thread that is mounted onsaid rod member,

said follower member having a projection on one side and having onanother side a substantially flat surface for co-acting with said oneside of said box like member which co-action prevents rotation of saidfollower member around said threaded member,

switch means located in said box like member opposite said opening andadjacent said threaded member,

said switch means being capable of being contacted by said projectionfrom said follower member,

said follower member being positioned on said threaded member at a pointadjacent said opening when said roll-curtain door is in the open orrolled up position,

7 said threaded member being rotated by said shaft upon and said switchmeans comprising a plurality of leaf springs that are held at adjacentedges and which have electrical contacts on their opposite ends.

References Cited UNITED STATES PATENTS 3/1939 Arcelon 200158 X 3/1965Schaefer 200-47 X 10 NEIL C. READ, Primary Examiner.

D. L. TRAFTON, Assistant Examiner.

1. A SWITCHING SYSTEM IN A BURGLAR ALARM SYSTEM FOR SIGNALING OPENINGMOVEMENT OF A ROLL-CURTAIN DOOR OR THE LIKE UPON OPENING OR CLOSING ANELECTRICAL CIRCUIT IN RESPONSE TO GIVEN ROTATIONAL MOVEMENT OF THEROLL-CURTAIN DOOR SHAFT, COMPRISING; A THREADED, MEMBER HAVING INTERNALTHREADS THAT ARE CAPABLE OF BEING ROTATED BY SAID SHAFT, A FOLLOWERMEMBER HAVING EXTERNAL THREADS THAT IS MOUNTED ON SAID THREADED MEMBER,MEANS FOR PREVENTING ROTATION OF SAID FOLLOWER MEMBER AROUND SAIDTHREADED MEMBER, AND SWITCH MEANS IN SAID ELECTRICAL CIRCUIT BEINGPOSITIONED ADJACENT SAID THREADED MEMBER FOR BEING ACTUATED THROUGHCONTACT WITH SAID FOLLOWER MEMBER.